QVT13 — QVTo: Extents, Models and Model Parameters

There is no mention of extent in Section 8.1 where one might hope to find an overview of the utility.

The proposed resolution of Issue 13103 clarifies the ability of ObjectExp to (re-)define the extent residence of a pre-existing object.

MappingParameter has some contradictory indications that an extent is bound by the callee rather than the caller.

Is this a consequence of the need for a MappingOperation to have a 1:1 correspondence to a QVTr Relation requiring the domain to be determined solely from the declaration? How is the inability of a Relation to have more than one parameter per domain accommodated when there can be more than one parameter per extent?

Specify the utility of an extent

There is no mention of extent in Section 8.1 where one might hope to find an overview of the utility.

The proposed resolution of Issue 13103 clarifies the ability of ObjectExp to (re-)define the extent residence of a pre-existing object.

MappingParameter has some contradictory indications that an extent is bound by the callee rather than the caller.

Is this a consequence of the need for a MappingOperation to have a 1:1 correspondence to a QVTr Relation requiring the domain to be determined solely from the declaration? How is the inability of a Relation to have more than one parameter per domain accommodated when there can be more than one parameter per extent?

Discussion

A section on Extents is sadly lacking; write it.

The confusing fiction that there is a correspondence between QVTo Model Parameters and QVTr Domains is best eliminated.